Helical coil forming machine

ABSTRACT

A pair of large wire supply rolls are rotatably supported by a cantilevered tubular shaft, and corresponding wires extend from the rolls to a coil forming rotor which is also supported by a cantilevered tubular shaft aligned axially with the roll support shaft. Wire is withdrawn from the wire supply rolls by rotation of the rotor which includes precisely driven wheels for feeding the wires through corresponding sets of casting rollers to form a continuous double helix nonrotating coil. A non-rotating mandrel projects through the roll support shaft for supporting the helical coil as it is being formed and progresses axially between a set of endless belts which feed the continuous coil from the coil forming rotor and control the pitch of the wire turns of the coil. A disc brake system is mounted on the roll support shaft for breaking the rotation of the wire supply rolls to control the tension in the wires, and the roll support shaft is pivotable in a horizontal direction to facilitate loading of new wire supply rolls into the machine. The machine is also adapted to be used with only one wire supply roll when only a single helix nonrotating continuous coil is required.

United States Patent [1 1 Lang [451 May 27, 1975 HELICAL COIL FORMINGMACHINE [75] Inventor: Ernest U. Lang, Niles, Mich.

[73] Assignee: Dayco Corporation, Dayton, Ohio [22] Filed: Mar. 22, I974[21] Appl. No.: 453,748

Related US. Application Data [62] Division of Ser. No. 343,617, March21, 1973, Pat.

[52] US. Cl l40/92.6; 72/138 [51] Int. Cl B2lf 3/00 [58] Field of Search72/66, 140, 134, 145, 138; l40/92.6, 103, 71 C, 71.5, 71; 339/15;174/47; 29/203 D [56] References Cited UNITED STATES PATENTS 3,124,1693/1964 Schade l40/7l.5 3,225,798 12/1965 Dessureau 140/71 X PrimaryExaminerC. W. Lanham Assistant Examiner-Robert M. Rogers Attorney,Agent, or FirmReuben Wolk [5 7] ABSTRACT A pair of large wire supplyrolls are rotatably supported by a cantilevered tubular shaft, andcorresponding wires extend from the rolls to a coil forming rotor whichis also supported by a cantilevered tubular shaft aligned axially withthe roll support shaft. Wire is withdrawn from the wire supply rolls byrotation of the rotor which includes precisely driven wheels for feedingthe wires through corresponding sets of casting rollers to form acontinuous double helix nonrotating coil. A non-rotating mandrelprojects through the roll support shaft for supporting the helical coilas it is being formed and progresses axially between a set of endlessbelts which feed the continuous coil from the coil forming rotor andcontrol the pitch of the wire turns of the coil. A disc brake system ismounted on the roll support shaft for breaking the rotation of the wiresupply rolls to control the tension in the wires, and the roll supportshaft is pivotable in a horizontal direction to facilitate loading ofnew wire supply rolls into the machine. The machine is also adapted tobe used with only one wire supply roll when only a single helixnonrotating continuous coil is required.

2 Claims, 7 Drawing Figures SHEET FIG-5 SHEET FIG-7 HELICAL COIL FORMINGMACHINE BACKGROUND OF THE INVENTION In the art of producing helical wirecoils having convolutions or turns of generally uniform diameter, it issometimes desirable to provide for producing the coil so that it doesnot rotate as it is being formed, thereby enabling the coil to beproduced in a continuous manner and then fed directly into a secondaryoperation or wound onto a spool. For example, U.S. Pat. No. 3,1 18,800discloses an apparatus for continuously forming a flexible conduit andwherein a nonrotating helical wire coil is fed directly into a tube offoamed plastics material. Nonrotating helical wire coils are alsointended to be continuously formed by the machines disclosed in U.S.Pat. Nos. 1,953,502 and 3,541,828. A continuously formed nonrotatinghelical wire coil may also be fed directly into one or more plasticextruder heads in a manner as disclosed in U.S. Pat. application Ser.No. 89,333, filed Nov. 13, 1970 and assigned to the assignee of thepresent invention, for continuously producing a reinforced flexibleplastic tube.

For some applications and uses of a wire reinforced flexible plasticstube or conduit, it is desirable to provide for a double wire helicalcoil so that the wires may be used as electrical conductors along thelength of the flexible conduit. For example, U.S. Pat. No. 3,314,039which issued to the assignee of the present invention, discloses the useof such a conduit in connection with a vacuum cleaner for supplyingelectrical power to a motor located at the end of a wand which isconnected to the vacuum tank by the flexible suction tube. In theproduction of such a flexible conduit having multiple wire helicalreinforcement, it is desirable to provide for continuously producing theconduit to achieve maximum manufacturing efficiency and to minimize thecost of the conduit.

SUMMARY OF THE INVENTION The present invention is directed to animproved machine or apparatus for continuously producing a nonrotatinghelical Wire coil and which is adapted for forming either a multiplewire helical coil or a single wire helical coil, whichever is desired.The apparatus of the invention also provides for producing a preciselyformed helical coil at a high speed and for conveniently loading newrelatively large supply rolls of wire into the machine. In general,these features and advantages and other features and advantages whichwill become apparent from the following detailed description, areprovided by apparatus including a cantileveredly supported horizontaltubular shaft which is adapted to support one or more supply rolls ofwire for rotation. The shaft also incorporates a brake system forrestraining the rotation of the wire supply rolls and is pivotablebetween a roll loading position and an operating position.

The wire supply roll support shaft is axially aligned with anothertubular shaft which supports a coil forming rotor having arms projectingaxially outboard of the wire supply rolls to support rollers fordirecting the wire from the supply rolls to wire feeding and castingmeans carried by the rotor. As a nonrotating helical wire coil is formedby rotation of the rotor and the wire supply rolls, the coil is formedon and guided by a mandrel initially supported by the supply rollsupport shaft. The pitch of the wire turns on the mandrel of thecontinuously formed helical coil, is controlled by a set of angularlydisposed endless belts which are driven in adjustable timed relationwith the rotation of the rotor. These belts further support the coil andthe mandrel on the center of rotation of the rotor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of ahelical coil forming machine constructed in accordance with theinvention;

FIG. 2 is a fragmentary perspective view of a double wire helical coilconstructed on the machine shown in FIG. 1; I

FIG. 3 is a vertical section generally through the axis of the wiresupply support mechanism;

FIG. 4 is a fragmentary elevational view of the wire feed wheels andwire casting rollers forming part of the coil forming rotor shown inFIG. 1;

FIG. 5 is a fragmentary section of the coil forming rotor takengenerally on the line 5-5 of FIG. 4;

FIG. 6 is a fragmentary axial section of the helical coil forming rotorshown in FIG. 1; and

FIG. 7 is an elevational view of the left end of the coil formingmachine shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT The machine of FIG. 1 isillustrated and described for continuously producing a double wirehelical coil 15 (FIG. 2) which includes a pair of plastic coated wires16 formed to produce helical wire turns 18 similar to the double wirehelical coil disclosed in above mentioned U.S. Pat. No. 3,314,039. Thecoil forming machine includes an elongated, fabricated steel base frame20 on which is mounted a generally C-shaped yoke-like pedestal 22. Ablock-like support member 24 (FIGS. 1 and 3) is supported by thepedestal 22 for pivotal movement on the vertical axis of a pair ofvertically aligned trunion pins 26 (FIG. 3). The member 24 supports oneend portion of a horizontally projecting cantilevered tubular shaft 28having opposite end portions which receive a set of fittings 29 and 31.

The shaft 28 is adapted to receive a pair of spools 32 (FIG. 3) on whichcorresponding supplies of wire 16 are wound to form a pair of wiresupply rolls R (FIG. 1). Each of the spools 32 is rotatably supported bya pair of annularcylindrical bearings 34 which provide for slight axialmovement of the spools 32 on the support shaft 28. A set of disc brakes35 are assembled on the shaft 28 adjacent opposite ends of each spool32, and the brakes are actuated or compressed axially with the spools 32by extension of a fluid cylinder 38 connected to a brake yoke member 39pivotally supported by the support member 24. The roll support shaft 28and the support block member 24 are adapted to be pivoted on the axis ofthe pins 26 to a laterally projecting position which provides forconveniently removing the empty spools 32 and for loading a new set ofwire supply rolls R onto the shaft 28. When the shaft 28 is returned toits operating position shown in FIGS. 1 and 3, the shaft support member24 is secured by a lever actuated lock pin 42.

As shown in FIG. 3, an elongated rigid cylindrical arbor or mandrel 45extends through the roll support shaft 28 and is concentricallysupported by the end fittings 29 and 31. The mandrel 45 is extendedthrough the shaft 28 after the shaft is positioned and locked in itsoperating position shown in FIG. 3. An opening 46 is formed within therear wall of the pedestal 22 to provide for inserting the mandrel 45into the shaft 28. The mandrel 45 has a diameter slightly larger thanthe inside diameter of the helical coil made of plastic coated wire 16to provide a snug fit of the coil 15 on the mandrel as the coil 15 isbeing formed.

A coil forming rotor (FIGS. 1 and 6) is supported for rotation by a pairof anti-friction bearings 51 which are mounted on a stationary tubularstub shaft 52. The shaft 52 projects cantileveredly from a housing 54(FIG. 1) which is mounted on a pedestal 56 secured to the base frame 20.The tubular shaft 52 is axially aligned with the supply roll supportshaft 28 in its operating position and receives the concentricallylocated mandrel 45.

The rotor 50 includes a tubular hub 56 which supports a head plate 58reinforced by a set of angular bracket members 59. A set of flyer arms62 project axially from the rotor head plate 58 and are located radiallyoutboard of the wire supply rolls R. Each of the flyer arms 62 supportsa corresponding set of guide rollers 64 to provide for directing thewire 16 from each of the supply rolls R to the head plate 58 of therotor 50.

Referring to FIGS. 4 and 5, the head plate 58 of the rotor 50 supports apair of diametrically opposed wire feed units each of which includes twosets of wire feed wheels 72 which positively grip the wire received fromthe corresponding inner guide roller 64. Each of the wires 16 is fedinwardly by the corresponding wheel 72 between a pair of spaced guideshoes 74 and into a corresponding set of casting rollers 76 rotatablysupported by an annular plate 77. Each set of casting rollers 76 isarranged to curl or deform the corresponding wire 16 beyond its elasticlimit to form a turn 18 around the mandrel 45. The wire turns 18 havesubstantially no stress so that upon subsequent removal from themandrel, the coil 15 will maintain its shape.

As shown in FIG. 5, each set of wire feed wheels 72 is mounted oncorresponding spindles 78 and 79. Spindie 79 is rotatably supported by ahousing 82 forming part of the corresponding wire feed unit 70. Spindle78 is rotatably supported by an eccentric bushing 83 which permits theuse of different diameter feed wheels 72. Each of the housings 82 alsosupports a gear drive train 84 and a set of change gears 85 which aredriven by a planetary gear 86 (FIGS. 5 and 6) engaging a sun gear 88secured to the rearward or outer end portion of the stationary rotorsupport shaft 52. The interchangement of different diameter feed wheels72 and change gears 85, provides for precisely controlling the feed ofthe wires 16 and for producing coils of different diameters and pitches.The coil forming rotor 50 is driven by a variable speed electric motor90 (FIG. 1)

- which has a shaft 91 connected by a pulley 92 and an endless flexiblegear belt 93 to a pulley 94 (FIGS. 1 and 6) secured to the cylindricalhub 57 of the rotor 50. An idler pulley 96 maintains a predeterminedtension in the gear belt 93.

The double wire nonrotating helical coil 15 is continuously produced orformed on the stationary mandrel 45 by rotation of the rotor 50 in thedirection indicated by the arrow in FIG. 1. That is, after the supplyrolls R of wire are mounted on the stationary support shaft 28, and themandrel 45 is extended through the shaft 28 and through the rotorsupport shaft 52, the wires 16 are directed from the supply rolls Raround the corresponding guide rollers 64 to the corresponding wire feedunits 70. The wires 16 are initially fed by the feed wheels 72 betweenthe corresponding casting rollers 76, by manually rotating or joggingthe rotor 50.

After the wires 16 are started, and rotation of the rotor 50 continues,the pair of wires 16 are positively and simultaneously fed inwardly at arate which corresponds to the length of each turn 18 with eachrevolution of the rotor so that the double wire helical coil 15 fitssnugly on the mandrel 45 with substantially no stress in the wires 16.As the rotor 50 rotates on the shaft 52, the pull on the wires 16 causesthe wire supply rolls to rotate on the shaft 28 at a speed or rate whichis slightly greater than the rotational speed or rate of the rotor 50.This additional rotational speed of the wire supply rolls R is due tothe fact that with each revolution of the rotor 50, a length of wire 16corresponding to the length of a helical turn 18, is unwound or pulledfrom each of the supply rolls R. The tension in the wires 16 from thesupply rolls R to the wire feed wheels 72 is controlled by actuation ofthe brake cylinder 38.

As the nonrotating helical coil 15 is formed on the mandrel 45 and movesforwardly through the tubular stationary rotor support shaft 52, thenonrotating helical coil 15 is gripped by a coil feeding mechanism 100(FIG. 1). The coil feeding mechanism 100 includes a series of threeendless flexible V-belts 102 which are uniformly arranged around themandrel 45 (FIG. 7). Each of the belts 102 is directed around a set ofinner pulleys 104 and a larger outer pulley 106. The inner pulleys 104of each set are arranged to provide an inner axial run of thecorresponding belt 102 for frictionally engaging the outer surface ofthe nonrotating helical coil 15. Each set of pulleys 104 and 106 aresupported by a corresponding axially extending radial plate 108 which isradially adjustable relative to a stationary frame member 110 byadjustment of a corresponding screw 112.

Referring to FIG. 7, one of the pulleys 104 of each set of pulleys, ismounted on a shaft which also supports a pulley 116. An endless V-belt118 is directed around the pulleys 116 and a set of guide pulleys 119.Another pulley 123 is mounted on the shaft which supports the upperpulleys 104 and 116, and an endless flexible V- belt 124 is directedaround the pulley 123 and a set of guide rollers 126 (FIG. 1) to apulley 127 mounted on the output shaft of a gear reducer 128. The inputshaft of the reducer 128 is connected to the motor shaft 91 through aspeed variator 132 and a set of couplings 133.

By adjusting the speed of the variable speed reducer 132, the speed ofthe belts 102 is adjusted to change the pitch of the wire turns 18 ofthe nonrotating helical coil 15 as it is being produced by rotation ofthe rotor 50. However, a change in the speed of the motor 90 to increaseor decrease the speed of forming the helical coil 15, automaticallychanges the speed of the coil feed belts 102 so that the preselectedpitch of the wire turns 18 remains constant.

From the drawings and the above description, it is apparent that ahelical coil forming machine constructed in accordance with the presentinvention, provides desirable features and advantages. For example, themachine provides for. continuously and rapidly producing a multiple wirenonrotating helical coil from large supply rolls. The machine is alsoadapted for producing a single wire helical coil, simply by feeding onlyone wire 16 into the rotor 50 and between one set of casting rollers 76.As a series of mandrels 45 or discrete sections of mandrels are fed inend-to-end abutting relation through the wire supply roll support shaft28, the mandrels provide for guiding the continuously formed helicalcoil between the coil feed belts 102 to assure that the coil ispositively fed from the coil forming rotor 50 as the coil is formed. Inaddition, the speed of the coil feed belts 102 may be infinitelycontrolled relative to the speed of the rotor 50 by adjusting the speedvariator 132 so that the pitch of the helical turns 18 may beconveniently changed and precisely set while the nonrotating coil isbeing produced.

Another important feature is provided by the support of the wire supplyroll support shaft 28 for pivotal movement between its normal operatingposition (FIG. 1) and a laterally projecting loading position whereempty spools 32 may be conveniently removed and new wire supply rolls Rmay be conveniently mounted on the shaft 28. Furthermore, the discbrakes 35 cooperate with the wire supply rolls R when the brakes areenergized by actuation of the cylinder 38 to prevent overspinning of thewire supply rolls R and to control the tension within the wire 16extending from the supply rolls to the coil forming rotor 50. The wirefeed units 70 also cooperate to force the corresponding wires 16inwardly between the corresponding set of casting rolls 76 to deformeach of the wires into the desired radius of curvature substantiallyconforming to the diameter of the mandrel 45.

While the form of coil forming apparatus herein described constitutes apreferred embodiment of the coil forming invention, it is to beunderstood that the invention is not limited to this precise form ofapparatus, and that changes may be made therein without departing fromthe scope and spirit of the invention, For example, the machine could beeasily modified to form a continuous nonrotating triple wire helicalcoil, for example, if it were desirable to add a ground wire within aflexible plastic conduit requiring two electrically conducting wires.

The invention having thus been described, the following is claimed:

1. Apparatus for continuously producing a nonrotating coil havinghelical wire turns of substantially uniform diameter, comprising meansfor rotatably supporting a plurality of wire supply rolls positioned intandem relation, a coil forming rotor including means for receiving awire from each of the wire supply rolls and for deforming the wiresbeyond their elastic limit into interfitting continuous wire turns,means for supporting said rotor for rotation on an axis substantiallyaligned with the axis of rotation of the wire supply rolls, means forrotating said rotor, means on said rotor for directing the wires fromthe corresponding wire supply rolls to said wire deforming means, meansfor guiding the coil axially from said rotor after the coil is formed byrotation of said rotor, means for feeding the wire coil from said rotoras the coil is being formed, and means for varying the speed of saidfeeding means relative to the speed of rotation of said rotor to providefor changing the pitch of the wire turns of said coil.

2. Apparatus as defined in claim 1 including means for braking therotation of the wire supply rolls to control the tension in the wiresextending from the rolls to said coil forming rotor.

1. Apparatus for continuously producing a nonrotating coil havinghelical wire turns of substantially uniform diameter, comprising meansfor rotatably supporting a plurality of wire supply rolls positioned intandem relation, a coil forming rotor including means for receiving awire from each of the wire supply rolls and for deforming the wiresbeyond their elastic limit into interfitting continuous wire turns,means for supporting said rotor for rotation on an axis substantiallyaligned with the axis of rotation of the wire supply rolls, means forrotating said rotor, means on said rotor for directing the wires fromthe corresponding wire supply rolls to said wire deforming means, meansfor guiding the coil axially from said rotor after the coil is formed byrotation of said rotor, means for feeding the wire coil from said rotoras the coil is being formed, and means for varying the speed of saidfeeding means relative to the speed of rotation of said rotor to providefor changing the pitch of the wire turns of said coil.
 2. Apparatus asdefined in claim 1 including means for braking the rotation of the wiresupply rolls to control the tension in the wires extending from therolls to said coil forming rotor.